Process for the utilization of peat.



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THOMAS RIGBY, or DUMFRIES, sco'rLAND, AND NiLS TESTRUP, OELONDON,ENGLAND, ASSIGNORS T0 WETCARBONIZING LIMITED, OF LONDON, ENGLAND.

PROCESS FOR THE UTILIZATION OF PEA'I.

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No Drawing.

To all whom it may concern:

Be it known that we, THOMAS RIGBY, a

subject of the King of Great Britain and Ireland, and resident of 61Loreburn street, Dumfries, Scotland, and blue TEs'rRUP, a subject of theKing of Great Britaln and Ireland, and resident of 3 'Dean Farrarstreet, London, S. W., England, have invented a certain newand usefulImproved Process for the Utilization of Peat, of which the following isa specification.

This invention relates tothe utilization of peat by gasification of thesame in gas producers adapted for by-product recovery, see for instancethe co-pending application Ser. No. 712,745, filed August 1st, 1912.Before peat can be utilized in such a way, however, it is necessary toremove water from it and this has usually been attempted by drainage andsubsequentair drying on the bog or in drying sheds. Again, proposalshave been made first to decompose water-binding matters which the peatcontains, and then to dewater the product by filter-pressing. A

It has been proposed to effect drying of peat artificially as byexposing peat after drainage to products of combustion but suchprocesses have never found practical application owing to the largeamount of heat required to eifect drying in relation to the calorificvalue of the dried peat fuel obtained.

The object of the present invention is to provide an improved processcapable of application on a largescale for utilizing peat bygasification in by product recovery gas producers.

The present invention consists in removing such a portion of the waterof the peat as renders it suitable for disintegration, then reducing itto a finely divided condition and exposing it for the desired period inthis condition in hot products of combustion of gases generated inby-product recovery gas producers to which some or all of the treatedmaterial is supplied. The drying is preferably carried out by passingthe products of combustion through a duct leading to cyclone separatorsor other like means into which duct the disintegrated peat isintroduced, the rate of the flow of the gases, the length of the ductand other factors being adjusted so that when the material which iscarried by the gases reaches Specification of Letters Patent.

Patented June 22, 1915.

Application filed November 23, 1912. Serial N 0. 733,214.

the separating means it has the desired dryness. The treated material isconsolidated into cakes or briquets for gasification.

By proceeding according to the present invention regular working isreadily obtained as no difliculty arises in obtaining weather or otherconditions such as will enable the preliminary drying necessary (say to70% water content) to be uniformly obtained. Moreover the fuel obtaineddoes not require the use in the producer of so high a blast pressure andproduces less dust and consequent fouling of the tar and loss ofby-products, principally ammonia, than fuel obtained by air drying.

In carrying the invention into elfect in the preferred form thedryinginstallation is adapted to reduce the water content of a part ofthe material to an intermediate value only say to a water content of 50%and to dry the remainder practically completely the former quantitybeing consolidated into cake form and the latter briqueted in any usualway, the proportions so treated being chosen to givethe desired averagemoisture content in the fuel when they are mixed for charging into theproducen, Such a mixed charge gives a mechanically strong fire and greatfreedom from dust in the gases. This method may be carried out bydividing the drying into two distinct stages, the hottest products ofcombustion effecting the second stage of drying and the waste gases fromthis stage being utilized to effect the first stage of the drying. Thusthe gases which may be wholly or in part exhaust gases from internalcombustion engines consuming producer gas and used to supply power or togenerate electricity or may be obtained by combustion under any othersuitable condition of the producer gas are introduced into a fine whenthe finely divided peat already to some extent dried in the firststage,is added as by a rotary pocket valve, the solid being conveyed by thegases to a series of cyclone separators where it is removed and thewaste gases still containing a certain amount of their heat have addedto them the raw material e., the peat which simply by pressing, drainingor air drying had its water slightly reduced). This material is nowcarried by the gases to a further series of separators where it isthrown down and partly supplied to the rotary valve beincreased ammoniayields and freedom from dust are obtainable. V 7

Either in consolidating the partly dried material or in briqueting themore completely dried peat any suitable binder such as tar orpitch (e.9., from the by-product plant) may be used.

.Having now described our invention, What we claim as new and desire tosecure by Letters Patent is 'L'Method of utilizing peat according towhich the latter ispartially dried, then at least in part pulverized,dried further as-a powder suspended in hot products of combustion, andthereupon gasified to yield gas from which the products required fordrying are ultimately obtained.

2. Method of utilizing peat according to which the latter is partiallydried, then at least in part pulverized, further dried as a powdersuspended in hot products of combustion, and thereupon gasified to yieldgas which, after being treated for the recovery of by-products, isutilized to generate power and thereby supply the hot products requiredin drying the peat. V

3. Method of utilizing peat according to which the latter is filterpressed, then at least in part pulverized, dried further as powdersuspended in hot products of combustion, consolidated and thereupongasified to yield gas from which the products required for drying areultimately obtained.

4. Method of utilizing peat according to which the latter is filterpressed, then at least in part pulverized, further dried as a powdersuspended in hot products of combustion, consolidated and thereupon gasifled to yield gas which, after being treated for the recovery ofby-products, is'uti'lized to generate power and thereby supply the hotproducts required in drying the peat.

5; Method of utilizing peat in which the peat is filter pressed, a partthereof then pulverized, and the powder so obtained dried'by suspensionin hot products of combustion, then briqueted, and along with anotherpart of the filter pressed peat is gasified to yield gas from which theproducts of combustion required for drying the peat are ultimatelyobtained.

6. Method of utilizing peat in which the peat is filter pressed, a partthereof then Copies of this patent may be obtained for pulverized, andthe powder so obtained dried by suspension in hot products ofcombustion, then-briqueted, andalong with another-part of the filterpressed peat is gasified to yield gas which, after being treated for therecovery of ammonia, is utilized to generate power and thereby yield thehot products of combustion required for drying the peat, p p

7. Method of utilizing peat according to which the latteris filterpressed, then at least a part thereof pulverized and further driedbybeing'sus aended aspo'wder in hot products of combustion which, aftereffecting the final drying of the powder are utilized to dry the moisterpowder, whereupon the powder is consolidated andgasified to yield gasfrom which the products necessary for drying the peat are ultimatelyobtained.

8. .Method of utilizing peat, in which the peat is filterpressed, a partthereof pulverized and the powder so obtained dried by suspension in acurrent ofhot'products of combustion which, after having been cooled ineflecting the" final drying of thepowder,

are further utilized to effect drying of the moister powder, whereuponthe powder. is

briqueted, and along. with another part of the filter, pressed peat isgasified to yield gaswhich, after being treated for therecovery ofby-products, is utilized to generate power and thereby yield the hotproducts of combustion required for drying the peat.

9. Method of utilizing peat accordingto which the latter is partiallydried by filter pressing, then pulverized, further dried as a powdersuspended in hot productsof combustion, and thereupon .gasified to yieldwhich, after being treated for the recovery of ammonia, is utilized togenerate power and thereby supply the hot; products required in dryingthe peat.

10. Method of utilizing peat according to which at least part of thelatter is partially dewatered, then pulverized, further dewa teredas apowdersuspended in hot products of combustion and thereupon" burned toyield hot products of combustion for thedewatering.

In testimony whereof we have signed our names to this specification inthe presence of two subscribing witnesses.

' THOMAS RIGBY.

I NILS TESTRUP.

Witnesses to signature of Thomas Rigby:

Bummer H. MArTHEws, ANDREW H. SKILLING.

Witnesses to-signature of Nils Testrup:

BERTRAM H. MATTHEWS, E. C. WALKER.

five cents each, by addressingvthe Commissioner of arena, Washington, D.C.

